Gaskell, who also serves the University of California Cooperative Extension in San Luis Obispo County, revealed his observations on new crop possibilities recently at a vegetable production seminar in Guadalupe.

Noting that several coastal operations are producing multiple brassica crops, oriental vegetables, or heirloom vegetables, he has worked with sweet onion, edamame vegetable soybeans, fall asparagus, and blueberries for the past seven years.

“These may fit well into existing operational patterns, such as oriental vegetables with vegetables or blueberries with strawberries. But developing a new crop involves much more than planting it and seeing it grow.”

The first order of business is to monitor the marketplace, followed by a learning curve about whether the new crop will produce commercially with a return on investment. Then the crop has to fit with the existing marketing and transportation systems. The process can take years, and his trials are aimed at developing cultural data.

Sound marketing plan

“And before you get too far into it, you have to have a sound marketing plan, otherwise you may later encounter a major bottleneck that has nothing to do with growing the crop.”

After evaluating material from the National Soybean Germplasm Laboratory, he more recently turned to varieties that are commercially available. Edamame soybeans, a popular snack food in Japan, are gaining interest from oriental cultures and health food outlets in the U.S. The majority is frozen product from Taiwan, at nearly $4 per pound, but some fresh supplies from California are beginning to appear.

Soybeans are narrowly adapted because the flowering, podding and fruit set are governed a combination of day length and temperature. While data for conventionally grower soybeans in the United States is readily available, it is practically nonexistent for edamame.

Several seed companies have edamame varieties commercially grown in Japan, and Gaskell had trials on several varieties in 2001 at Arroyo Grande. Days to harvest for the crop range, according to variety, from 84 to 92.

Reliable data

“We are starting to get some reliable data with these varieties at different planting dates. The important characteristics for quality are three-seeded pods and the number of pods per 500 grams. The bigger pods have more harvestable yield,” he said.

In late-summer or early-fall asparagus trials, Gaskell is evaluating nearly two dozen varieties, including both traditional California and New Jersey varieties and some from Europe. Prices at this time are double that of the traditional period, and California product would be fresher than imported.

He said he sees some potential in forgoing the spring harvest season, allowing early fern development, cutting down the plants in July or August, and harvesting the new spears. However, he added, only additional seasons will prove whether the idea is viable.

“The market is there, when domestic asparagus switches from the 30-pound box to the 11- or 13-pound box in mid-July. The price stays high until the first of the asparagus comes out of the Imperial Valley in early January.”

Blueberry deal

Thus far, he said, the asparagus trial data is sorting out with significant differences showing between varieties, some better adapted to the schedule than others.

The blueberry potential is being pursued in several parts of California because the fruit captures an early spring market when prices are attractive.

“We are sorting out cultural practices, such as driving the soil pH down, using the low-chill, southern high-bush varieties, and pruning management.” Data collection is made over about three seasons to show indications.

In Santa Barbara County, he added, soils tend to have pH of 6.5 to 7.5, or more, and blueberries need soil in the range of 4.5 to 5. Applications of sulfur, initially and annually thereafter, are made to adjust pH, and wood waste is applied to heavy soils to keep proper moisture levels for the shallow-rooted plants.

Nurseries in Oregon, Michigan, North Carolina, and Florida supply southern high-bush plants. Oregon sources also have the late-season, “rabbit eye” types which Gaskell plans to evaluate for potential in extending the coastal season.

Aware of imports

Interested growers should be aware of imports from Chile, Argentina, Canada, and other origins, and the peaks early and late in the season for coastal California blueberries.

In a curious array of packaging, blueberries containers can vary from 3.5 ounces in the early season to 2-pound packs when the crop is more plentiful in mid-summer.

According to data on the 1998-2000 season at the Los Angles Terminal Market, prices spike to about $50 per flat in early May.

“It looks like we can successfully grow blueberries on the coast from Watsonville to San Diego and hit at least a portion of the market window.”

Blueberries are also being evaluated for the San Joaquin Valley at the Kearney Agricultural Center at Parlier, but Gaskell said the harvest season for coastal counties extends over a longer period than that of the SJV.